Joint construction

ABSTRACT

A stucco-covered, curtain wall construction employs a joint including an elongate L-shaped casing bead and an elongate generally wing-shaped drainage cap member. The two joint components form a horizontally-disposed, structurally yielding joint between outer covering panel sections. The two joint components provide ventilation and water drainage between the windward and leeward sides of the wall.

United States Patent Conway [4 1 June 27, 1972 54] JOINT CONSTRUCTION[56] References Cited [72] Inventor: Donald J. Conway, Glenview, 111.UNITED STATES PATENTS [73] Assignee: United States Gypsum Company,Chicago, 2,856,766 10/1958 Ill. 2,922,385 l/1960 3,056,233 10/1962 [22]Filed. Aug. 19, 1970 3,192,577 7/1965 Appl' 65351 I PrimaryExaminer-Price C. Faw,Jr.

Rehm. Application Data Attorney-George E. Verhage and John K. Wise [62]Division of Ser. No. 771,821, 0m. so, 1968, Pat. No. [571 ABSTRACT Astucco-covered, curtain wall construction employs a joint including anelongate L-shaped casing bead and an elongate [52] U.S.Cl ..52/367,52/573 e er lly wing-shaped drainage cap member. The two joint [51] Int.Cl. ..E04b 1/70, E041" 13/06 components form a horizontally-disposed,structurally yield- Field Search 52/364, 3 ing joint between outercovering panel sections. The two joint components provide ventilationand water drainage between the windward and leeward sides of the wall.

7 Claims, 8 Drawing Figures P'A'TE'N'TEDJum I972 sum 1 or 2 Donald J.Conw INVI ENTOR.

BY John Kenneth Wise George E. Verhage Dana M. Schmidt ATTORNEYSPATENTEDquuzv m2 sum 2 or 2 Donald J. Conway INVENTOR.

S Y E N R 0 T A ew BUM hi m m m e M e n n m a JG V. B

JOINT CONSTRUCTION RELATION TO PENDING APPLICATIONS This application isa divisional application of my application Ser. No. 771,821 filed onOct. 30, 1968, now U.S. Pat. No. 3,568,391.

BACKGROUND OF. THE INVENTION This invention relates to a water-shedding,expansible joint structure for use in a stucco-covered, curtain type,generally exterior wall. The term curtain wall" is applied to a type ofbuilding construction in which an exterior non-load bearing wall issupported in front of the structural frame like a curtain. Moreparticularly, this invention relates to a casing bead and a drainage capor flashing in a ventilated curtain wall construction providing waterdrainage and a degree of equalization of air pressure between the wallcavity and the surrounding atmosphere.

Curtain type, as well as some other exterior panel walls having anexposure to rain driven by winds having a velocity as high as 90 milesper hour in certain areas of the United States, have been vulnerable toadmittance of wind-carried water as well as to insufficient drainage ofaccumulated water from the cavity of the wall, or the interval betweenthe exterior wall and the inner, supporting framing shell of the wallconstruction.

oftentimes rain enters into the wall cavity wherever a joint line hasnot been sealed, or adequately sealed, against ingress of rain. Cracks,poorly designed joint lines or other types of leaky constructions whichopen to the atmosphere allow for admittance of water, and in many casessuch constructions do not provide for drainage of water from the cavityof the wall.

The problem of infiltrated water has become crucial where the exposedwallarea is large and vulnerable to rain driven by high velocity winds.The problem often is aggravated in cases where the water entering thewall cavity accumulates to a sufficient degree to cause leakage into theinterior of the building with resulting damage. Such damage includescorrosion to metal parts, wetting and compacting of insulation materialsand damage to building interiors and furnishings. Also, in some caseswater entering the wall cavity does not drain to the exterior of thebuilding, but soaks down through the wall portions causing structuraldeterioration and discoloration to visible exterior portions of thewall.

Previously, in stucco as well as other types of curtain walls, variousattempts have been made to overcome this problem. Such attempts haveincluded high quality workmanship on existing constructions, the use ofsealants and weepholes, and pressure equalization systems of varioustypes.

In the normal use of the joint components provided by this invention, anelongate wing-shaped drainage cap is horizontally aligned on theexterior of a building frame or shell which may be formed ofplaster-board sheathing. The cap has a central, flexible joint portionwhich serves as a drainage ledge and which is V-shaped in cross section.The central V is integrally formed with opposed coplanar wings, eitheror both of which may be fastened to the sheathing.

A casing bead of generally L-shaped configuration is set in place withthe short leg of the L resting on the upper surface of the cap jointportion. The back of the bead has a plurality of flutes or groovesformed therein and extends above the upper wing of the drainage cap. Thebend is secured in place, and stucco or other cementitious material maybe formed into a panel over the sheathing on the short leg of the beadwhich serves as a panel edging and thickness gauge. Preformed panels mayalso be secured in place on the bead leg. Water formed in or enteringinto the wall cavity may readily drain to the. exterior, through thesegrooves by gravity, as will hereinafter be explained in detail. Also,water driven into the joint between the cap and bead will be restrainedor baffled" in the restricted groove portions and will not readily passinto the wall eevlty behind the panels.

It In an object ol this invention, therefore, to provide a slmpie andinexpensive casing bead and drainage cap joint construction which isadapted to be disposed horizontally at the base of each course of eitherstucco-covered wall sections or inlaid panel sections to prevententrance into the joint of wind-driven water, while also providingdrainage of condensation or other accumulated moisture from the wallcavity to the exterior of the building.

It is another object of this invention to provide a novel jointconstruction comprising a casing bead and drainage cap which functionsto provide partial equalization of air pressure between the wall cavityand the exterior atmosphere. Such equalization eliminates one of themajor causes of water infiltration into a wall, that is, a pressuredifferential between the cavity and the exterior.

Another object of this invention is to provide a casing bead memberhaving water draining grooves or flutes fonned in the rear surfacethereof and also'incorporates therein a screeding lip flange for thegauging of stucco which may be applied thereto.

It is a further object of this invention to provide a casing bead memberhaving a plurality of grooves or flutes of predetermined height so as toprovide for the development of hydrostatic pressure by confined watercolumns. The columns oppose incoming water driven between the jointcomponents by the wind striking the exterior of the casing wallconstruction; such grooves provide communication from the cavity of thewall to the exterior of the wall.

Another object of this invention is to provide the combination of anelongate casing bead member and an elongate drainage cap member to beinstalled in relatively movable engagement whereby adjacent sections ofthe curtain wall which are subjected to thermal or structural stressesmay move relatively to each other in the vertical plane, suchpermissible movement obviating possible damage to the sections of thecurtain wall.

It is another object of this invention to provide for noveljoint-forming components in a casing wall construction which isadaptable to be erected in either the vertical plane as is normal, orplanes inclined to the vertical if so desired.

The above, and other objects of this invention will become more apparentfrom the following detailed description when read in the light of theaccompanying drawings and the appended claims.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary perspective viewillustrating a casing bead and drainage cap member illustrated inassembled relationship with a portion of a stucco panel disposed innormal position on the casing bead;

FIG. 2 is a fragmentary exploded view illustrating rear surface portionsof a casing bead and drainage cap provided by this invention;

FIG. 3 is a fragmentary perspective view illustrating rear surfaceportions of a casing bead and drainage cap in assembled relationshipwith a fragment of a stucco panel formed thereon;

FIG. 4 is a fragmentary sectional view of the joint components providedby this invention shown in normal assem' bled relationship in amulti-storied construction;

FIG. 5 is a fragmentary perspective view of a modified casingbeadprovided by this invention;

FIG. 6 is a perspective view of a clip member adapted to join drainagecap members together in horizontal alignment;

FIG. 7 is a fragmentary sectional view illustrating the manner in whicha drainage cap and modified casing bead member may be employed inconjunction with a building soffit; and

FIG. 8 is a fragmentary perspective view of a casing head installed inthe foundation region of a building.

DESCRIPTION OF THE INVENTION Referring now more particularly to FIG. I,an exterior view is therein depicted of a portion of a curtain wall. Ajoint is illustrated in the wall which is formed by an upper casing beaddisposed in overlying relationship with a lower drainage cap 12. Theexternal curtain wall sections are composed of discrete sections orsheets of stucco 14, each of which rests on a ledge 16 of a casing bead10. In addition to ledge 16, each casing bead has a back 18 which isaffixed by suitable securing members to supporting framing members suchas gypsum board sheathing 20 or the like. The latter sheathing isnormally secured to spaced vertical supports which may be wood or steelmembers which are readily erected in place. The joint components 10 and12 may also be supportably attached directly to such vertical members(not illustrated in FIG. 1).

Inasmuch as a curtain wall by definition comprises a buildingconstruction in which exterior panels are non-load bearing but aresupported by an inner supporting framework, it will be seen from FIG. 1that the curtains or stucco sections 14 are disposed as a curtain overthe sheathing 20. The specific details of construction of the casingbead 10 and the drainage cap 12 are more apparent from FIG. 2. It willbe noted from FIG. 2 that the back 18 of each casing bead may haveapertures 22 formed therein to facilitate passage of a securing meanssuch as nails 26 illustrated in FIG. 1. The ledge 16 of each casing beadconnects the back portion with a tenninal flange 28 disposedsubstantially parallel to the back 18 and extending in the samedirection therewith from the interposed ledge 16. Grooves or flutes 30,one of which is illustrated in FIG. 2, are arranged at regular intervalssuch as 3 inch intervals in the back 18 of the casing bead 10.

In the normal course of erection, the first joint element to be erectedis the drainage cap 12. As will be seen from FIG. 2, the cap 12comprises an upper wing member 32 which is connected to a lower wingmember 34 by means of an interposed, V-shaped connecting joint 36. Thelower wing 34, while in parallel relationship with the upper wing, needonly have a height adequate to facilitate mounting, and may be one-halfthe height of upper wing 32. The V-shaped connecting portion of thedrainage cap terminates in a drip flange 38. Flange 38 is of U-shapedcross-sectional configuration and comprises a continuation of an upperslanted web and drainage surface 40 and a lower, substantiallyhorizontally disposed web portion 42. Drainage surface 40 is preferablyinclined at an angle of about or to the horizontal. Fastener receivingapertures 44 may be disposed at regular intervals in each of the wingportions 32 and 34 of the drainage cap as is most clearly seen from FIG.2.

In the course of joint construction, a drainage cap 12 is horizontallyaligned and secured in place to supporting frame member such as thesheathing 20 shown in FIG. 1. The casing head 10 is then supported onthe upper web 40 of the drainage cap so that the right-angle juncturebetween the back 18 and the horizontal ledge 16 of the casing bead isnestably received in the juncture between the upper wing 32 and theupper web portion 40 of the drainage cap. The casing bead will now bedisposed horizontally and is fixed by suitable fasteners such as nailsor the like to the supporting framework. After the two joint components10 and 12 are fixedly secured in place, a forrnable cementitiousmaterial such as stucco will be applied over the sheathing so that asheet 14 will be formed, resting upon ledge 16 of the casing bead asillustrated in FIG. 1.

In order to secure firm engagement between each stucco panel 14 and theopposed sheathing 20, an expanded metal mesh may be secured in placeagainst the sheathing and over back 18 of the casing head by clipmembers 48 or large head nails or other equivalent securing means. Theexpanded metal layer 46 is adapted to function as means for keying thestucco in which the mesh is embedded to the supporting sheathing 20. Tofurther assist in the keying action, the expanded metal sheet 46 may bedepressed out of a single plane at regular intervals to further assuredesired engagement with the stucco material or other hardenablematerial. As will be noted from FIG. I, the thickness of the finishedstucco panel 14 substantially coincides with the width of the ledge 16of the casing bead. As is seen from the illustrated joint of FIG. 4, theupper edge portion of each stucco panel may be formed between the rearsurface 34 of a drainage cap member and the opposed depending dripflange 38.

The spacing between the supporting ledge 16 of each casing bead and theoverlying lower web portion 42 of a drainage cap member determines theheight of each stucco panel 14 which is formed in situ and employed inthe illustrated type of curtain wall construction. The specificdimensions of the panels employed for forming the curtain wall arediscretionary with the builder; a typical stucco panel will havedimensions of 4 to 6 feet in height and of 8, 10 or 12 feet in length.Each ledge 16 of each casing bead may have centrally disposed drainageapertures 50 formed therein at regular spaced intervals to assist in thedrainage of any water which may seep between the back 18 of the casingbead, the ledge 16 and the stucco panel 14 which is formed thereover(see FIGS. 1 and 3). The temtinal flange or lip portion 28 of the casingbead may function as a screeding member, as may the depending dripflange 38 of an overlying drainage cap. Accordingly, after the formablestucco or other cementitious composition is applied over the back 18 ofthe casing bead and the overlying surface of the sheathing, a smoothingor leveling instrument may employ the depending and upstanding flangeportions as screeds in forming the appropriate thickness of each panel14.

FIG. 3 illustrates the intended function of the drainage cap memberafter the same has been erected in place in a curtain wall construction.The upper drainage web 40 of each drainage cap 12 is inclined to thehorizontal at a slight angle. This slight angle also functions to spacethe adjacent horizontal courses of the stucco panels 14. The spacingbetween the panels is determined by the magnitude of the divergencebetween the web portions 40 and 42 of each central V-shaped portion 36of each drainage cap member. Inasmuch as the web portions 40 and 42 ofeach V-shaped portion 36 may resiliently move relative to each other,upon the thermal expansion of the cementitious material defining eachpanel in a curtain wall, the same will be allowed to expand in thevertical direction because of the spring or resiliency in the connectingportion 36. Lateral expansion of panels 14 may be accommodated byvertical framing members well known in the art, such as l" beamsengaging panels between opposed flanges. Such structures are notillustrated and comprise no portion of this invention.

The upper web portion 40 of each drainage cap in conjunction with theundersurface of each ledge 16 of each casing bead defines an exit way 37for the vertical grooves 30 formed in the rear surfaces 18 of the casingbeads. Assuming that a high velocity wind carrying entrained water isblowing against the exterior cladding panels 14 of the curtain wallconstruction illustrated, water will be forced into the V-shaped openingand rise in the grooves 30 formed in the back of the casing bead member.The water columns in the grooves 30 will form hydrostatic heads opposingthe force of the wind and water blowing into the openings betweenadjacent, parallel panel sections. The grooves 30 will serve as a meansfor equalizing the pressure between the atmosphere on the exterior ofthe stucco panels 14 and the interior cavity of the wall.

The grooves must have an effective cross-sectional area and geometry topermit water drainage. If the cross-sectional area of the groove is toosmall, inadequate drainage results. If the cross-sectional area is toolarge, any water in the groove does not maintain a suflicient continuityto provide a hydrostatic head functioning as a floating damper to thewind blowing into the openings between the panels or stucco sections.

Also, if the cross-sectional geometry of the grooves 30 possessesconstricted portions, surface tension of the water, or even entraineddirt particles, is liable to restrict adequate and desirable flow withinthe groove. Grooves of generally semicircular configuration having asmooth wall trough in the configuration of a V or an easy swept curve,and having a dimension of at least about 3/32 inch at the highestgapping have been found practical and desirable. Maximum gappings ofabout 56 inch are contemplated by this invention. Spacing between thegrooves may vary; a simple pattern of uniform spacing on 3 inch centershas been found to be effective and practical.

By way of a specific example, a casing bead of the type shown in thefirst four views of the drawing may have a lip flange 28 of 3/16 inch inheight, a ledge 16 one inch in width and a back portion of 6 inches inheight.

Table 1 below indicates preferred relative dimensions between the heightof the back portion of a casing bead and the height of the upper wingportion of an' underlying drainage cap.

TABLE I Casing Drainage Cap Bead Height Upp r Wing Height 4% Inches 2%Inches 5% Inches 3% inches 6% Inches 4% Inches 7 Inches 5 InchesUtilizing certain data taken from Climatological Data, United StatesDepartment of Commerce, Weather Bureau 1961 the following Table IIindicates the wind velocities effectively resisted by the casing beadsand drainage caps of Table I, the beads having flutes of substantiallyuniform cross section.

A modified drainage cap construction 10a is illustrated in FIG. 5. Cap100 has a concavity formed in the rear surface 180 thereof, the rearsurface being bent slightly along a middle axis 54. The slight concavityenables a spring action to be effected when the casing bead is securedin place against a supporting, planar sheathing surface. Thus themodified casing bead construction 10a is assured of secure, rattle-freeengagement with the underlying sheathing surface or surfaces upon beingnailed in place.

Modified casing bead 100 also illustrates grooves 300 which are slightlyangled to the vertical so as to provide a more tortuous path for anywater which is driven between the casing bead and underlying drainagecap. The groove portion 30a formed in the upper portion of casing beadback 18a in FIG. 5 forms angles when joining the lower groove portions304 formed in the lower half portion of the back 180 of the casing bead10a. The concavity illustrated in casing bead 10a may obviously beformed" in casing bead 10 without altering the vertical disposition ofthe grooves 30. Also, the angled grooves 30a may be formed in a casingbead 10 having a planar rear surface portion 18 without a concavity. Thedepth of the concavity in the modified casing beads is fairly slight,being in the nature of approximately My inch at its deepest point.

The casing bead and drainage cap constructions provided by thisinvention are adaptable to a variety of uses. Thus, the casing bead 10may be employed by itself at the floor line in a concrete course or slabconstruction as illustrated in FIG. 8. The casing bead having thecladding panel 14 provides communication between the exterior atmosphereand the cavity of the wall by means of grooves 30, the casing bead 10being secured directly to the slab 56 by appropriate securing means.

The casing bead and drainage cap may also be employed for purposes ofventilating a soffit construction as illustrated in FIG. 7. A modifiedcasing bead 13 is therein illustrated supported from a roofing deck 58,and in conjunction with the underlying drainage cap, forms a bame memberproviding a ventilating opening into the underlying soffit space formedin part by the framing member 60 and soflit board 61.

FIG. 4 is illustrative of the casing bead and drainage cap provided bythis invention employed in a multi-storied construction in whichspandrel 62, defining the juncture between adjacent floor members,supports a steel shelf angle 66 by means of suitable fasteners,notillustrated. Sheathing 68 is secured to vertical supports 70 whichengage runner members 72 at opposed end portions; the runners in turnengage the shelf angle. In addition to the illustrated casing bead 10and drainage cap 12, FIG. 4 also illustrates the utilization of aflashing strip 74' which may be employed for assisting the drainage ofwater from the cavity of thewall to the exterior of the building bydirecting the flow of condensate or other water onto the upper webportion 40 of the illustrated drainage cap 12. The flashing 74 may be astrip of water-resistant tar paper, or even deformable metal which isrust resistant.

FIG. 6 illustrates a splicing clip 76 which may be employed to assurehorizontal continuity and closure of drainage caps 12. Clips 76 i have aU-shaped clip portion 78 adapted to nestably receive adjacent portionsof drip flanges 38 arranged in a horizontal course. In normal use clips76 are interposed between the casing beads and drainage caps.

It is seen, therefore, that a novel joint construction has been providedwhich is particularly adapted for use in curtain wall constructions. Thenovel casing bead and drainage cap effect a number of useful functionsand may be employed in a number of useful applications, as is obviousfrom the above description of the constructions illustrated in thedrawings.

The novel curtain wall joints enable water which is forced into thecavity of the wall behind the exterior facing to readily drain therefromby gravity, and also enables any condensate formed in the wall cavity todrain to the exterior of the wall without causing any damage. The novelventing grooves formed in the rear surface of the casing bead alsofunction as a communicating path enabling pressure to equalize betweenthe exterior end interior cavity of the curtain wall. I

vAlthough the foregoing description has been specific with respect tostucco or other cementitious composition which is fonned into panels insitu and placed on the described casing bead members, it should beappreciated that the above described joint components may also beemployed in conjunction with preformed panel members such as cast cementslabs which may be fitted into place on the ledge of the casing bead andfixed in place by means of grouting which assures the establishment of acontinuous seal between the supporting casing bead and the inlaidmembers forming the panel supported by the casing bead. The providedjoint components may, of course, be employed in a variety of structuresnot defining what is technically a curtain wall" construction. Thematerials of composition for the components should be of adequatestrength and water resistant to serve the described P p It is apparentfrom the foregoing description that a number of modifications may bemade in the construction above described. This invention is tobe limitedonly by the scope of the appended claims.

I claim:

1. A wall joint construction comprising a casing bead having a grooved,substantially planar back integrally formed with a ledge portion joinedthereto at substantially right angles and adapted to engage lowerportions of a first mass of surfacing material; an elongated drainagecap having upper and lower coplanar wings joined by a flexible webconnection of substantially V-shaped cross section, the upper wingportion being disposed in surface contact with a lower grooved portionof the casing bead back; the drainage cap lower wing and a lower portionof the flexible web engaging the rear surface and top edge portionsrespectively of a second mass of surfacing material disposed beneathsaid first mass in substantially coplanar relationship, the casing beadledge portion being movable with the first mass of of surfacing materialand the drainage cap lower web portion being movable with the secondmass of surfacing material whereby relative movement between thesurfacing masses in the vertical plane results in flexing of the capweb.

2. The joint construction of claim 1 in which said casing bead ledgeportion has an upstanding flange and said drainage cap flexible web hasa depending lip; said flange and lip being in substantially the sameplane.

3. A wall joint construction comprising a casing bead having a backintegrally formed with ledge means along a line of juncture', said ledgebeing adapted to engage a first section of wall surfacing, drainage capmeans having a back portion adapted to be supported by a supportingsurface, a downwardly disposed drainage means directly connected to saidback portion along a line of juncture and cap means for engaging theupper edge portion of a second section of wall surfacing, integrallyformed with said drainage means and resiliently movable relativethereto; said casing bead back having a plurality of grooves formed inthe rear surface thereof defining open end, water-retaining passagewayswhen said casing bead support means-back juncture is nestably receivedin the juncture between said drainage means and back portion of saiddrainage cap means.

4. The wall joint construction of claim 3 in which said drainage capdrainage means has a depending lip and said casing bead ledge means hasan upstanding flange; said lip and flange lying in substantially thesame plane.

5. The wall joint construction of claim 3 in which said passageways aresubstantially uniform in crox section and have lengths between about 2and 6 inches.

6. The wall joint construction of claim 5 in which said grooves have across-sectional width of the order of between 3/32 inch and A inch.

7. The wall joint construction of claim 3 in which a wall surfacingmaterial is supported as said ledge means, and means for keying saidsurfacing material to said supporting surface is secured to saidsupporting surface and embedded in said wall surfacing.

l i t I i

1. A wall joint construction comprising a casing bead having a grooved,substantially planar back integrally formed with a ledge portion joinedthereto at substantially right angles and adapted to engage lowerportions of a first mass of surfacing material; an elongated drainagecap having upper and lower coplanar wings joined by a flexible webconnection of substantially V-shaped cross section, the upper wingportion being disposed in surface contact with a lower grooved portionof the casing bead back; the drainage cap lower wing and a lower portionof the flexible web engaging the rear surface and top edge portionsrespectively of a second mass of surfacing material disposed beneathsaid first mass in substantially coplanar relationship, the casing beadledge portion being movable with the first mass of of surfacing materialand the drainage cap lower web portion being movable with the secondmass of surfacing material whereby relative movement between thesurfacing masses in the vertical plane results in flexing of the capweb.
 2. The joint construction of claim 1 in which said casing beadledge portion has an upstanding flange and said drainage cap flexibleweb has a depending lip; said flange and lip being in substantially thesame plane.
 3. A wall joint construction comprising a casing bead havinga back integrally formed with ledge means along a line of juncture; saidledge being adapted to engage a first section of wall surfacing,drainage cap means having a back portion adapted to be supported by asupporting surface, a downwardly disposed drainage means directlyconnected to said back portion along a line of juncture and cap meansfor engaging the upper edge portion of a second section of wallsurfacing, integrally formed with said drainage means and resilientlymovable relative thereto; said casing bead back having a plurality ofgrooves formed in the rear surface thereof defining open end,water-retaining passageways when said casing bead support means-backjuncture is nestably received in the juncture between said drainagemeans and back portion of said drainage cap means.
 4. The wall jointconstruction of claim 3 in which said drainage cap drainage means has adepending lip and said casing bead ledge means has an upstanding flange;said lip and flange lying in substantially the same plane.
 5. The walljoint construction of claim 3 in which said passageways aresubstantially uniform in cross section and have lengths between about 2and 6 inches.
 6. The wall joint construction of claim 5 in which saidgrooves have a cross-sectional width of the order of between 3/32 inchand 1/2 inch.
 7. The wall joint construction of claim 3 in which a wallsurfacing mAterial is supported as said ledge means, and means forkeying said surfacing material to said supporting surface is secured tosaid supporting surface and embedded in said wall surfacing.